NORTH PHILADELPHIA (WPVI) -- The number of mumps cases tied to Temple University took a big jump today.

Health officials now say 49 people are either confirmed or suspected of having mumps - 11 more than yesterday.

Just yesterday another major university, Indiana University in Bloomington, said it's got an outbreak, with at least 3 cases of mumps.

The director of student health did say they expected to see more cases.

All but 3 of the people with the mumps are in Philadelphia. The others are in the suburban counties.

But all have ties to Temple.

12 are confirmed cases, while 37 are suspected, based on their symptoms.

Temple's outbreak began about 2 weeks ago, and it is the latest in nearly two dozen outbreaks on college campuses in the past few years.

Unlike the recent measles outbreaks, in most mumps cases, students have been vaccinated.

But Doctor Kristen Feemster, medical director of the immunization and communicable diseases program of the Philadelphia Health Department, says several factors may be making mumps more likely at universities.

"Over time, your immune response might decrease a little bit - probably about the time you're a young adult, and on a college campus," Dr. Feemster says.

"A college campus is a close-knit community, where there are probably more opportunities for transmission than you might have in other places," she adds.

The mumps virus is spread by droplets from secretions from the mumps virus.

Dr. Feemster says some people may be infected, but because they've been vaccinated, they're not showing all the classic symptoms such as swollen salivary glands.

So they may infect others.

Just like the flu, even if you get sick, the vaccine can help prevent severe complications.